The negligent student of biology will be forgiven for thinking individual survival is the only naturally prescribed goal. The anomaly of constitutionally communal species aside—ants, bees, and the like—the replicating unit is the single animal, compelled to interact with its kin only by the necessity of procreation and, for some, the expediency of collaborative hunting or defence. Even then, others seem merely instrumental, adopted and discarded as individual goals dictate. Examples of sacrifice, say, in the animal kingdom are seen as either aberrations or illusory anthropomorphizing. Our biological selfishness is inescapable, we are told, for it is itself the product of another: the selfishness of genes, competing in evolution's lawless market.